The Octave analyzer tool (RTA) supports both exponential (Lp) and linear (Leq) averaging of the signal in each whole or 1/3-octave frequency band. For exponential averaging, Fast, Slow, and Impulse time weightings are supported. For linear averaging, the average level is calculated over the entire duration of the measurement.

SignalScope's built-in documentation includes information on how to access the averaging options.

Well, I'd like to be able to take RTA measurements, moving the mic around the listening position where the listeners head would be situated during the 20 second interval, and have the RTA average the measurements taken during the 20 second interval.

Yes. With those settings, you'll get the average sound level over 20 seconds in each whole or 1/3 octave band, plus an overall (full bandwidth) average level. You can see the overall level by tapping the graph to turn on the cursor.

Yes. With those settings, you'll get the average sound level over 20 seconds in each whole or 1/3 octave band, plus an overall (full bandwidth) average level. You can see the overall level by tapping the graph to turn on the cursor.